So I'm not subbing all the work out if that is your previous experience. 

You buy the property, you give the tenant notice of a pending increase, they pack up and leave, then you spruce it up and rent it at market rate so it's a profitable investment.When egg prices double, do you think the local grocer cries in his coffee every morning about how inflation is impacting his customers?

Duplexes are worth quite a bit more per sqft than Fourplexes as there is a larger buyer pool and it opens to the non-investor customer.

The potential for a loan call is higher and higher with sub to the more parties you involve if that makes sense.Trying to take down four homes sub to and then do remodels to them all, and then list them on short-term rental sites, and get full permitting and ok for not just the STR, but for your renovations and all prior renovations maybe done without a permit, while on subto, sounds like a pretty big mess to me.I would consult with a sub to specialist and prepare for the potential of having all the loans called at some point.

This service also subs the legal work out. 

I used several lease templates that I found as a starting point, then created custom leases for my properties from those, and had my lawyer review them.

Like others mentioned sub $150-180k doesn't seem worth it, especially in blue states. 

Nothing beats a custom optimized CRM to fit your needs and how you do business.I honestly feel like everyone selling CRM try really hard to make people believe they need an "out-of-the-box" system, but this truly HAS to be customized to how you manage your leads.For Lead generation we leverage GrumpyHare. 

I clearly illustrated there is at least one customer saying they have issues.

There are a lot of opportunities to keep it full while negating the full time management/customer service aspect.